The site SurvivalAfterDeath | CienciasPsíquicas, in Spanish, has much information about psychical research, particularly about mediumship and the topic of survival of death. There is a section presenting links to many important books, (click here), many of which have been taken from other digital libraries such as Internet Archive and Google Books. Here are some examples.

These are only a few examples of many other books available in this collection. In addition, the are many issues of the Annals of Psychical Science, and of the Proceedings and Journal of the American Society for Psychical Research.